8. Iliofemoral vessel characteristics that would preclude safe placement of 22F or 24F for Cohort B and 14F or 16F for the S3 Cohorts (including NR7/NR8) introducer sheath such as severe obstructive calcification. Severe tortuosity or minimum average vessel size less than 7 mm (5.5 mm S3 Cohorts and NR7/NR) (Transfemoral).